Sen. Patty Murray of Washington, a key Democratic leader on education policy, made her case against private-school vouchers in a 20-page memo to her Senate colleagues Wednesday, arguing that “school choice” sounds good in theory but falls short in practice.

President Trump has promised to pour billions of dollars into expanding choice initiatives, including taxpayer-funded vouchers for private and religious schools. Education Secretary Betsy DeVos is a longtime advocate for such efforts, arguing that they provide poor children with life-changing opportunities.

But voucher programs too often fail to hold private schools accountable for their students’ performance, fail to serve children in rural areas, and fail to protect the rights of students with disabilities and other vulnerable young people, wrote Murray, the ranking Democrat on the Senate Committee on Health, Education, Labor and Pensions.

School choice is a “false choice,” she wrote, arguing that the way to provide children with a better education is to invest in public schools instead of private alternatives. “The only true student and family agenda is one that delivers on the idea that every child, parent, and family should have the choice to attend a high-quality public school.”

Murray, a former preschool teacher, has a strong record as a dealmaker who knows how to reach across the aisle, and she worked with Sen. Lamar Alexander (R-Tenn.) to negotiate a bipartisan revision of the nation’s main education law in 2015.

But that spirit of compromise in education has evaporated in recent months with Trump’s election and his nomination of DeVos to serve as education secretary. Murray accused Alexander of ramming DeVos’s nomination through the Senate without proper scrutiny. When Republican lawmakers voted this month to overturn an Obama-era education regulation, Murray said they had chosen a “retreat from bipartisanship.”

Now, the debate over vouchers — stoked by Trump’s proposal to invest $250 million in a new federal voucher program, even as he seeks to slash other education programs and domestic spending generally — is shaping up to be the latest in a long list of polarizing issues in Washington.

Democrats generally oppose vouchers, while Republicans tend to support them. Alexander, chairman of the education committee, has said that K-12 vouchers are no more objectionable than the popular G.I. Bill, which helps veterans pay for tuition at the college of their choice, including at private and religious institutions.

DeVos has argued that vouchers are one strategy to make sure that parents have access to whatever school will best meet their child’s needs. “Every child is different, with varying skills and learning styles. We shouldn’t then force all children into a one-size-fits-all education system,” she told a gathering of state school board members this week. “Our education approaches should be as varied as the students they serve.”

Murray argued in her memo Wednesday that vouchers are sold on the premise that parents make the best educational choices for their children. But private schools often do not have to publish the information parents need to make informed decisions, she argued, pointing to states such as Arizona, where private schools do not administer the same tests as public schools, making it impossible for parents to compare performance across all academic institutions.

“Without this information about whether students are learning to read, write, do arithmetic, and scientifically reason, schools and parents do not know whether the school is delivering on its end of the bargain,” she wrote.

Many voucher programs also do not require teachers to be certified and do not hold private schools to the same financial accountability standards and open-meetings and public-records laws that public schools must follow, Murray wrote.

She said vouchers carry a hidden cost for students with disabilities, who in many states must give up their rights under federal law to receive tuition subsidies. And she argued that for rural communities, far from the nearest private school, vouchers are at best irrelevant.

The better way forward, she argued, is to invest in “high-quality neighborhood schools,” and to ensure that all schools receiving federal funds meet high standards of accountability and transparency and abide by federal civil rights laws.